Abstract: A rotary torque-transmitting device has co-rotating driving and driven members and at least one pair of co-planar roller elements transmitting a torque load through respective line contacts with said members, at least one of which contacts is obliquely offset to produce a force component acting against a resilient bias for urging the rollers to counter-rotate from their load-transmitting positions to disengage the drive or trigger a load sensor. The line contacts are on portions of the driving and driven members that overlap each other transversely to the plane of said pair of rollers to permit a minimum oblique offset of the contact line and thereby increase sensitivity. The roller elements may be cylindrical rollers with axes parallel to the rotary axis of the device and the line contacts along their length.

Abstract: A rotary torque transmission device has at least one pair of balls or rollers transmitting a torque load through respective contact points or lines with driving and driven members of the device and a contact point or line with each other. The contact points (or lines) do not lie on the same line (or plane) whereby the torque load produces an offset force. This is resisted by resilient means and increases with the torque load until the force overcomes said resistance and causes substantially friction-free rolling of the balls or rollers on said contact points or lines. In different embodiments the rolling movement disengages the drive through the device or it is utilized to stop the drive input.